diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ArmorTypeConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ArmorTypeConverter.java
deleted file mode 100644
index d6d1d59..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ArmorTypeConverter.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.annotation.NonNull;
-import androidx.room.TypeConverter;
-
-import com.majinnaibu.monstercards.data.enums.ArmorType;
-
-public class ArmorTypeConverter {
-
-    @TypeConverter
-    public static String fromArmorType(@NonNull ArmorType armorType) {
-        return armorType.stringValue;
-    }
-
-    @TypeConverter
-    public static ArmorType armorTypeFromStringValue(String stringValue) {
-        return ArmorType.valueOfString(stringValue);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ArmorTypeConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ArmorTypeConverter.kt
new file mode 100644
index 0000000..a15f5eb
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ArmorTypeConverter.kt
@@ -0,0 +1,19 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import com.majinnaibu.monstercards.data.enums.ArmorType
+import com.majinnaibu.monstercards.data.enums.ArmorType.Companion.valueOfString
+
+object ArmorTypeConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromArmorType(armorType: ArmorType): String {
+        return armorType.stringValue
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun armorTypeFromStringValue(stringValue: String?): ArmorType {
+        return valueOfString(stringValue!!)
+    }
+}
\ No newline at end of file
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ChallengeRatingConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ChallengeRatingConverter.java
deleted file mode 100644
index 3d9712c..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ChallengeRatingConverter.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.annotation.NonNull;
-import androidx.room.TypeConverter;
-
-import com.majinnaibu.monstercards.data.enums.ChallengeRating;
-
-public class ChallengeRatingConverter {
-
-    @TypeConverter
-    public static String fromChallengeRating(@NonNull ChallengeRating challengeRating) {
-        return challengeRating.stringValue;
-    }
-
-    @TypeConverter
-    public static ChallengeRating challengeRatingFromStringValue(String stringValue) {
-        return ChallengeRating.valueOfString(stringValue);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ChallengeRatingConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ChallengeRatingConverter.kt
new file mode 100644
index 0000000..a8ce89e
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ChallengeRatingConverter.kt
@@ -0,0 +1,19 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import com.majinnaibu.monstercards.data.enums.ChallengeRating
+import com.majinnaibu.monstercards.data.enums.ChallengeRating.Companion.valueOfString
+
+object ChallengeRatingConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromChallengeRating(challengeRating: ChallengeRating): String {
+        return challengeRating.stringValue
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun challengeRatingFromStringValue(stringValue: String?): ChallengeRating {
+        return valueOfString(stringValue!!)
+    }
+}
\ No newline at end of file
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ListOfTraitsConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ListOfTraitsConverter.java
deleted file mode 100644
index 7a0e2ef..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ListOfTraitsConverter.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.room.TypeConverter;
-
-import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
-import com.majinnaibu.monstercards.models.Trait;
-
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.List;
-
-public class ListOfTraitsConverter {
-    @TypeConverter
-    public static String fromListOfTraits(List<Trait> traits) {
-        Gson gson = new Gson();
-        return gson.toJson(traits);
-    }
-
-    @TypeConverter
-    public static List<Trait> listOfTraitsFromString(String string) {
-        Gson gson = new Gson();
-        Type setType = new TypeToken<ArrayList<Trait>>() {
-        }.getType();
-        return gson.fromJson(string, setType);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ListOfTraitsConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ListOfTraitsConverter.kt
new file mode 100644
index 0000000..266fef1
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/ListOfTraitsConverter.kt
@@ -0,0 +1,24 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import com.majinnaibu.monstercards.models.Trait
+import java.util.*
+
+object ListOfTraitsConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromListOfTraits(traits: List<Trait?>?): String {
+        val gson = Gson()
+        return gson.toJson(traits)
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun listOfTraitsFromString(string: String?): List<Trait> {
+        val gson = Gson()
+        val setType = object : TypeToken<ArrayList<Trait?>?>() {}.type
+        return gson.fromJson(string, setType)
+    }
+}
\ No newline at end of file
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfLanguageConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfLanguageConverter.java
deleted file mode 100644
index b076a4d..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfLanguageConverter.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.room.TypeConverter;
-
-import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
-import com.majinnaibu.monstercards.models.Language;
-
-import java.lang.reflect.Type;
-import java.util.HashSet;
-import java.util.Set;
-
-public class SetOfLanguageConverter {
-
-    @TypeConverter
-    public static String fromSetOfLanguage(Set<Language> languages) {
-        Gson gson = new Gson();
-        return gson.toJson(languages);
-    }
-
-    @TypeConverter
-    public static Set<Language> setOfLanguageFromString(String string) {
-        Gson gson = new Gson();
-        Type setType = new TypeToken<HashSet<Language>>() {
-        }.getType();
-        return gson.fromJson(string, setType);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfLanguageConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfLanguageConverter.kt
new file mode 100644
index 0000000..6192daf
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfLanguageConverter.kt
@@ -0,0 +1,24 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import com.majinnaibu.monstercards.models.Language
+import java.util.*
+
+object SetOfLanguageConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromSetOfLanguage(languages: Set<Language?>?): String {
+        val gson = Gson()
+        return gson.toJson(languages)
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun setOfLanguageFromString(string: String?): Set<Language> {
+        val gson = Gson()
+        val setType = object : TypeToken<HashSet<Language?>?>() {}.type
+        return gson.fromJson(string, setType)
+    }
+}
\ No newline at end of file
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfSkillConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfSkillConverter.java
deleted file mode 100644
index 6f2ee90..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfSkillConverter.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.room.TypeConverter;
-
-import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
-import com.majinnaibu.monstercards.models.Skill;
-
-import java.lang.reflect.Type;
-import java.util.HashSet;
-import java.util.Set;
-
-public class SetOfSkillConverter {
-
-    @TypeConverter
-    public static String fromSetOfSkill(Set<Skill> skills) {
-        Gson gson = new Gson();
-        return gson.toJson(skills);
-    }
-
-    @TypeConverter
-    public static Set<Skill> setOfSkillFromString(String string) {
-        Gson gson = new Gson();
-        Type setType = new TypeToken<HashSet<Skill>>() {
-        }.getType();
-        return gson.fromJson(string, setType);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfSkillConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfSkillConverter.kt
new file mode 100644
index 0000000..7e8f77d
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfSkillConverter.kt
@@ -0,0 +1,24 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import com.majinnaibu.monstercards.models.Skill
+import java.util.*
+
+object SetOfSkillConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromSetOfSkill(skills: Set<Skill?>?): String {
+        val gson = Gson()
+        return gson.toJson(skills)
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun setOfSkillFromString(string: String?): Set<Skill> {
+        val gson = Gson()
+        val setType = object : TypeToken<HashSet<Skill?>?>() {}.type
+        return gson.fromJson(string, setType)
+    }
+}
\ No newline at end of file
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfStringConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfStringConverter.java
deleted file mode 100644
index c09dcaa..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfStringConverter.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.room.TypeConverter;
-
-import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
-
-import java.lang.reflect.Type;
-import java.util.HashSet;
-import java.util.Set;
-
-public class SetOfStringConverter {
-
-    @TypeConverter
-    public static String fromSetOfString(Set<String> strings) {
-        Gson gson = new Gson();
-        return gson.toJson(strings);
-    }
-
-    @TypeConverter
-    public static Set<String> setOfStringFromString(String string) {
-        Gson gson = new Gson();
-        Type setType = new TypeToken<HashSet<String>>() {
-        }.getType();
-        return gson.fromJson(string, setType);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfStringConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfStringConverter.kt
new file mode 100644
index 0000000..9b0bad6
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/SetOfStringConverter.kt
@@ -0,0 +1,23 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import java.util.*
+
+object SetOfStringConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromSetOfString(strings: Set<String?>?): String {
+        val gson = Gson()
+        return gson.toJson(strings)
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun setOfStringFromString(string: String?): Set<String> {
+        val gson = Gson()
+        val setType = object : TypeToken<HashSet<String?>?>() {}.type
+        return gson.fromJson(string, setType)
+    }
+}
\ No newline at end of file
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/UUIDConverter.java b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/UUIDConverter.java
deleted file mode 100644
index d775179..0000000
--- a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/UUIDConverter.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package com.majinnaibu.monstercards.data.converters;
-
-import androidx.annotation.NonNull;
-import androidx.room.TypeConverter;
-
-import java.util.UUID;
-
-public class UUIDConverter {
-
-    @NonNull
-    @TypeConverter
-    public static String fromUUID(@NonNull UUID uuid) {
-        return uuid.toString();
-    }
-
-    @TypeConverter
-    public static UUID uuidFromString(String string) {
-        return UUID.fromString(string);
-    }
-}
diff --git a/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/UUIDConverter.kt b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/UUIDConverter.kt
new file mode 100644
index 0000000..4673c14
--- /dev/null
+++ b/Android/app/src/main/java/com/majinnaibu/monstercards/data/converters/UUIDConverter.kt
@@ -0,0 +1,18 @@
+package com.majinnaibu.monstercards.data.converters
+
+import androidx.room.TypeConverter
+import java.util.*
+
+object UUIDConverter {
+    @JvmStatic
+    @TypeConverter
+    fun fromUUID(uuid: UUID): String {
+        return uuid.toString()
+    }
+
+    @JvmStatic
+    @TypeConverter
+    fun uuidFromString(string: String?): UUID {
+        return UUID.fromString(string)
+    }
+}
\ No newline at end of file